Why Heterochromatin Is Inactive?

Transcriptionally inactive heterochromatin is vital to sustaining stable chromosome structure throughout the cell cycle. ... Heterochromatin is densely packed and inaccessible to transcription factors so it is rendered transcriptionally silent (Richards and Elgin 2002).

Is heterochromatin genetically inactive?

Heterochromatin mainly consists of genetically inactive satellite sequences, and many genes are repressed to various extents, although some cannot be expressed in euchromatin at all. Both centromeres and telomeres are heterochromatic, as is the Barr body of the second, inactivated X-chromosome in a female.

Is heterochromatin always inactive?

There are two types of heterochromatin. Portions of the chromosome that are always inactive. Facultative Heterochromatin is one way to get a position effect.